Since day one, my PW screen has been changing. Most days it's uniform, some days I get pink spots. I posted about it - but it seems to be an isolated case, I don't see many people talking about screen spots 'coming and going'.

Today, after I updated, I looked at the screen and it was more pinkish than ever in the upper half. A clear split between the upper and lower halves.
After reading for about an hour, it's gone.

I have noticed this on all the PW's I have had, to be honest. Mine are never there all the time. They do seem to be affected by the environment to some extent.